<html>
    <head>
        <style>
            table, th, td {border: 1px solid black; border-collapse: collapse;}
            td {padding:30px;}
            table {margin: 30px;}
        </style>
    </head>
    <body>
        <h1>Header</h1>
        <p>This is the first paragraph.</p>
        <table>
            <tr>
                <td>A</td>
                <td>B</td>
            </tr>
            <tr>
                <td>
                    <table>
                        <tr>
                            <td>A1</td><td>B1</td><td>C1</td>
                        </tr>
                        <tr>
                            <td>D1</td>
                                <td>
                                    <table>
                                        <tr>
                                            <td>I</td><td>II</td>                                            
                                        </tr>
                                        <tr>
                                            <td>III</td><td>IV</td>                                            
                                        </tr>
                                        <tr>
                                            <td>V</td>
                                            <td>
                                                <table>
                                                    <tr>
                                                        <td>E1</td><td>E2</td>
                                                    </tr>
                                                    <tr>
                                                        <td>E3</td><td>E4</td>
                                                    </tr>
                                                </table>
                                            </td>                                            
                                        </tr>
                                        <tr>
                                            <td>VII</td><td>VIII</td>                                            
                                        </tr>
                                    </table>
                                </td>
                            <td>F1</td>
                        </tr>
                    </table>
                </td>
                <td>2...</td>
            </tr>
        </table>
        After table
    </body>
</html>